I just discovered the details of this buried away in an old sketch book. Last year while visiting Liverpool I had my head scanned as part of a scheme were they were building a catalogue of 3D head scans to act as a guide for doctors doing reconstructive surgery at Alder Hay Children’s Hospital. A rather good application of technology I thought and fortunately the idea is to extrapolate average dimensions rather than rely on individual heads.
http://www.theheadspaceproject.co.uk/headscape-shot/131116114523/